Like cockles, mussels are best left in the fridge overnight in a bowl of lightly salted water with plain flour scattered over (ingesting the flour encourages the mussels to spit out any sand and grit.)

After soaking, drain the mussels in a colander then leave under cold, running water for a few minutes to get rid of the flour.

Heat a large saucepan (with a lid) over a high heat until hot.

Quickly throw in the mussels and the white wine. Cover and cook over a high heat for 2-3 minutes, shaking the pan till all the mussels have opened. Don't overcook them or you'll end up with rubbery flesh.

Drain them in a large colander, placed over a bowl to catch the cooking liquor. Once the mussels are cool enough to handle, remove them from the shells and set them aside in a bowl, discarding any that have not opened. Strain the cooking liquor through a muslin cloth into a bowl and reserve.

In another saucepan, melt the butter, and then sweat the onion until soft. Stir in the flour and curry powder, and then cook gently for a few minutes.

Add the cooking liquor from the mussels and stock, stir well and simmer for 10 minutes.

Stir in the cream, bring back to the boil and add the mussels to warm them through.

Finally, just before serving, add the spinach and ladle the soup into warmed bowls. Sprinkle liberally with snipped chives and serve with crusty bread.